1. Field of the Invention
The present invention relates to a living tissue cutting instrument which pulls a subcutaneous vessel under endoscopic observation and samples the pulled subcutaneous vessel.
2. Description of the Related Art
In recent years, in a Coronary Artery Bypass Grafting, as the blood vessel for bypassing, a blood vessel in inferior limb, for example, a great saphenous vein, of a patient himself/herself is often used. Living tissue harvesting apparatuses for harvesting the blood vessel of the inferior limb under endoscopic observation have been proposed, for example, in Japanese Unexamined Patent Application Publication No. 2004-008241.
The living tissue harvesting apparatus is composed of instruments such as a dissector, harvester, or the like. An endoscope can be inserted into the dissector and harvester, and the operator can sample the blood vessel while watching the endoscopic image. The dissector is inserted from a trocar which is a guiding tube set on an incision in the neighbor below the patient's knee, by being inserted through the entire length of the blood vessel to be sampled, gradually dissects the blood vessel and the peripheral tissues. The harvester is an instrument having a bipolar cutter used for electrically cutting a branch of the blood vessel dissected from the peripheral tissues by the dissector.
The bipolar cutter has a groove formed at the distal-end part and a pair of electrodes is provided such that the groove is held from the upper side and the lower side. If the bipolar cutter is moved forward, the branch enters into the groove of the distal-end part, then, the branch is cut with the blood being stanched by discharge of electricity from the two electrodes.